Economic Evolution and Structural Adjustment: Proceedings, Berkeley, California, USA, 1985

Since the beginning of the fifties, the ruling paradigm in the discipline of economics has been that of a competitive general equilibrium. Associated dynamic analyses have therefore been preoccupied with the stability of this equilibrium state, corresponding simply to studies of comparative statics. The need to permeate the boundaries of this paradigm in order to open up new pathways for genuine dynamic analysis is now pressing. The contributions contained in this volume spring from this very ambition. A growing circle of economists have recently been inspired by two distinct but complementary sources: (i) the pathbreaking work of Joseph Schumpeter, and (ii) recent contributions to physics, chemistry and theoretical biology. It turns out that problems which are firmly rooted in the economic discipline, such as innovation, technological change, business cycles and economic development, contain many clear parallels with phenomena from the natural sciences such as the slaving principle, adiabatic elimination and self- organization. In such dynamic worlds, adjustment processes and adaptive behaviour are modelled with the aid of the mathematical theory of nonlinear dynamical systems. The dynamics is defined for a much wider set of conditions or states than simply a set of competitive equilibria. A common objective is to study and classify ways in which the qualitative properties of each system change as the parameters describing the system vary

Models of self-organization in biological development

Bibliography: p. 297-320.In this thesis we thus wish to consider the concept of self-organization as an overall paradigm within which various theoretical approaches to the study of development may be described and evaluated. In the process, an attempt is made to give a fair and reasonably comprehensive overview of leading modelling approaches in developmental biology, with particular reference to self-organization. The work proceeds from a physical or mathematical perspective, but not unduly so - the major mathematical derivations and results are relegated to appendices - and attempts to fill a perceived gap in the extant review literature, in its breadth and attempted impartiality of scope. A characteristic of the present account is its markedly interdisciplinary approach: it seeks to place self-organization models that have been proposed for biological pattern formation and morphogenesis both within the necessary experimentally-derived biological framework, and in the wider physical context of self-organization and the mathematical techniques that may be employed in its study. Hence the thesis begins with appropriate introductory chapters to provide the necessary background, before proceeding to a discussion of the models themselves. It should be noted that the work is structured so as to be read sequentially, from beginning to end; and that the chapters in the main text were designed to be understood essentially independently of the appendices, although frequent references to the latter are given. In view of the vastness of the available information and literature on developmental biology, a working knowledge of embryological principles must be assumed. Consequently, rather than attempting a comprehensive introduction to experimental embryology, chapter 2 presents just a few biological preliminaries, to 'set the scene', outlining some of the major issues that we are dealing with, and sketching an indication of the current status of knowledge and research on development. The chapter is aimed at furnishing the necessary biological, experimental background, in the light of which the rest of the thesis should be read, and which should indeed underpin and motivate any theoretical discussions. We encounter the different hierarchical levels of description in this chapter, as well as some of the model systems whose experimental study has proved most fruitful, some of the concepts of experimental embryology, and a brief reference to some questions that will not be addressed in this work. With chapter 3, we temporarily move away from developmental biology, and consider the wider physical and mathematical concepts related to the study of self-organization. Here we encounter physical and chemical examples of spontaneous structure formation, thermodynamic considerations, and different approaches to the description of complexity. Mathematical approaches to the dynamical study of self-organization are also introduced, with specific reference to reaction-diffusion equations, and we consider some possible chemical and biochemical realizations of self-organizing kinetics. The chapter may be read in conjunction with appendix A, which gives a somewhat more in-depth study of reaction-diffusion equations, their analysis and properties, as an example of the approach to the analysis of self-organizing dynamical systems and mathematically-formulated models. Appendix B contains a more detailed discussion of the Belousov-Zhabotinskii reaction, which provides a vivid chemical paradigm for the concepts of symmetry-breaking and self-organization. Chapter 3 concludes with a brief discussion of a model biological system, the cellular slime mould, which displays rudimentary development and has thus proved amenable to detailed study and modelling. The following two chapters form the core of the thesis, as they contain discussions of the detailed application of theoretical concepts and models, largely based on self-organization, to various developmental situations. We encounter a diversity of models which has arisen largely in the last quarter century, each of which attempts to account for some aspect of biological pattern formation and morphogenesis; an aim of the discussion is to assess the extent of the underlying unity of these models in terms of the self-organization paradigm. In chapter 4 chemical pre-patterns and positional information are considered, without the overt involvement of cells in the patterning. In chapter 5, on the other hand, cellular interactions and activities are explicitly taken into account; this chapter should be read together with appendix C, which contains a brief introduction to the mathematical formulation and analysis of some of the models discussed. The penultimate chapter, 6, considers two other approaches to the study of development; one of these has faded away, while the other is still apparently in the ascendant. The assumptions underlying catastrophe theory, the value of its applications to developmental biology and the reasons for its decline in popularity, are considered. Lastly, discrete approaches, including the recently fashionable cellular automata, are dealt with, and the possible roles of rule-based interactions, such as of the so-called L-systems, and of fractals and chaos are evaluated. Chapter 7 then concludes the thesis with a brief assessment of the value of the self-organization concept to the study of biological development

Modeling complex cell regulation in the zebrafish circadian clock

The interdisciplinary "systems biology" approach of combining traditional biological investigations with tools from the mathematical and computer sciences has enabled novel insights into many highly complex and dynamic biological systems. The use of models has, for instance, revealed much about the intricate feedback mechanisms and acute importance of gene regulatory networks, and one such network of special note is our internal time keeper, or circadian clock. The circadian clock plays a pivotal role in modulating critical physiological processes, and has also been implicated, either directly or indirectly, in a whole range of pathological states. This research project investigates how the underlying dynamics of the circadian clock in the zebrafish model organism may be captured by a mathematical model, considering in particular the entrainment effect due to external cues such as light. Simulated data is contrasted with experimental results from different light regime experiments to validate the model and guide its refinement. Furthermore, various statistical methods are implemented to process the raw data and support its analysis. Extending the initial deterministic approach to take into account stochastic effects and additive population level effects emerges as a powerful means of representing the circadian signal decay in prolonged darkness, as well as light initiated re-synchronization as a strong component of entrainment. Consequently, it emerges that stochastic effects may be considered an essential feature of the circadian clock in zebrafish. A further cornerstone of the project is the implementation of an integrated simulation environment, including a Sequential Monte Carlo parameter estimation function, which succeeds in predicting a range of previously determined and also novel suitable parameter values. However, considerable difficulties in obtaining parameter values that satisfy the entire range of important target values simultaneously highlights the inherent complexity of accurately simulating the circadian clock

American Literature and Science

Literature and science are two disciplines are two disciplines often thought to be unrelated, if not actually antagonistic. But Robert J. Scholnick points out that these areas of learning, up through the beginning of the nineteenth century, “were understood as parts of a unitary endeavor.By mid-century they had diverged, but literature and science have continued to interact, conflict, and illuminate each other. In this innovative work, twelve leaders in this emerging interdisciplinary field explore the long engagement of American writers with science and uncover science’s conflicting meanings as a central dimension of the nation’s conception of itself. Reaching back to the Puritan poet-minister-physician Edward Taylor, who wrote at the beginning of the scientific revolution, and forward to Thomas Pynchon, novelist of the cybernetic age, this collection of original essays contains essential work on major writers, including Franklin, Jefferson, Poe, Emerson, Thoreau, Twain, Hart Crane, Dos Passos, and Charles Olson. Through its exploration of the ways that American writers have found in science and technology a vital imaginative stimulus, even while resisting their destructive applications, this book points towards a reconciliation and integration within culture. An innovative look at a neglected dimension of our literary tradition, American Literature and Science stands as both a definition of the field and an invitation to others to continue and extend new modes of inquiry. A thoughtful collection that reveals how the concept of ‘science’ has evolved from Franklin to cyberpunk, and how it has transformed American literary form and expression. —American Literature Innovative. . . . The first systematic examination of this neglected dimension of the American literary tradition. —American Renaissance Literary Reporthttps://uknowledge.uky.edu/upk_english_language_and_literature_north_america/1013/thumbnail.jp

Children\u27s Folklore

A collection of original essays by scholars from a variety of fields—including American studies, folklore, anthropology, psychology, sociology, and education—Children\u27s Folklore: A Source Book moves beyond traditional social-science views of child development. It reveals the complexity and artistry of interactions among children, challenging stereotypes of simple childhood innocence and conventional explanations of development that privilege sober and sensible adult outcomes. Instead, the play and lore of children is shown to be often disruptive, wayward, and irrational. The contributors variably con-sider and demonstrate contextual and textual ways of studying the folklore of children. Avoiding a narrow definition of the subject, they examine a variety of resources and approaches for studying, researching, and teaching it. These range from surveys of the history and literature of children\u27s folklore to methods of field research, studies of genres of lore, and attempts to capture children\u27s play and games.https://digitalcommons.usu.edu/usupress_pubs/1059/thumbnail.jp